Nuclear Energy | National Geographic Society (2023)

Nuclear energy is the energy in the nucleus, or core, of an atom.

Atoms

are tiny units that make up all matter in the universe, and energy is what holds the

nucleus

together. There is a huge amount of energy in an

atom

's dense

nucleus

. In fact, the power that holds the

nucleus

together is officially called the "strong force."

Nuclear energy

can be used to create electricity, but it must first be released from the

atom

. In the process ofnuclear fission,

atoms

are split to release that energy.

A nuclear reactor, or power plant, is a series of machines that can control

nuclear fission

to produce

electricity

. The fuel that

nuclear reactors

use to produce

nuclear fission

is pellets of the element uranium. In a

nuclear reactor

,

atoms

of

uranium

are forced to break apart. As they split, the

atoms

release tiny particles called fission products. Fission products cause other

uranium

atoms

to split, starting a chain reaction. The energy released from this

chain reaction

creates heat.

The heat created by

nuclear fission

warms the reactor's cooling agent. A

cooling agent

is usually water, but some

nuclear reactors

use liquid metal or molten salt. The

cooling agent

, heated by

nuclear fission

, produces steam. The

steam

turns turbines, or wheels turned by a flowing current. The

turbines

drive generators, or engines that create

electricity

.

Rods of material called nuclear poison can adjust how much

electricity

is produced.

Nuclear poisons

are materials, such as a type of the element xenon, that absorb some of the fission products created by

nuclear fission

. The more rods of

nuclear poison

that are present during the

chain reaction

, the slower and more controlled the reaction will be. Removing the rods will allow a stronger

chain reaction

and create more

electricity

.

As of 2011, about 15 percent of the world's

electricity

is generated by nuclear

power plants

. The United States has more than 100 reactors, although it creates most of its

electricity

from fossil fuels and hydroelectric energy. Nations such as Lithuania, France, and Slovakia create almost all of their

electricity

from nuclear

power plants

.

Nuclear Food: Uranium

Uranium

is the

fuel

most widely used to produce

nuclear energy

. That's because

uranium

atoms

split apart relatively easily.

Uranium

is also a very common element, found in rocks all over the world. However, the specific type of

uranium

used to produce

nuclear energy

, called U-235, is rare.

U-235

makes up less than one percent of the

uranium

in the world.

Although some of the

uranium

the United States uses is mined in this country, most is imported. The U.S. gets

uranium

from Australia, Canada, Kazakhstan, Russia, and Uzbekistan. Once

uranium

is mined, it must be extracted from other minerals. It must also be processed before it can be used.

Because nuclear

fuel

can be used to create nuclear weapons as well as

nuclear reactors

, only nations that are part of the Nuclear Non-Proliferation Treaty (NPT) are allowed to

import

uranium

or plutonium, another nuclear

fuel

. The treaty promotes the peaceful use of nuclear

fuel

, as well as limiting the spread of

nuclear weapons

.

A typical

nuclear reactor

uses about 200 tons of

uranium

every year. Complex processes allow some

uranium

and

plutonium

to be re-enriched or recycled. This reduces the amount of mining,

extracting

, and processing that needs to be done.

Nuclear Energy and People

Nuclear energy

produces

electricity

that can be used to power homes, schools, businesses, and hospitals. The first

nuclear reactor

to produce

electricity

was located near Arco, Idaho. The Experimental Breeder Reactor began powering itself in 1951. The first nuclear

power plant

designed to provide energy to a community was established in Obninsk, Russia, in 1954.

Building

nuclear reactors

requires a high level of technology, and only the countries that have signed the Nuclear Non-Proliferation Treaty can get the

uranium

or

plutonium

that is required. For these reasons, most nuclear

power plants

are located in the developed world.

Nuclear

power plants

produce renewable, clean energy. They do not pollute the air or releasegreenhouse gases. They can be built in urban or rural areas, and do not radically alter the environment around them.

The

steam

powering the

turbines

and

generators

is ultimately

recycled

. It is cooled down in a separate structure called a cooling tower. The

steam

turns back into water and can be used again to produce more

electricity

. Excess

steam

is simply

recycled

into the atmosphere, where it does little harm as clean water vapor.

However, the byproduct of

nuclear energy

is radioactive material.

Radioactive

material is a collection of unstable atomic nuclei. These nuclei lose their energy and can affect many materials around them, including organisms and the environment.

Radioactive

material can be extremely toxic, causing burns and increasing the risk for cancers, blood diseases, and bone decay.

Radioactive waste is what is left over from the operation of a

nuclear reactor

.

Radioactive

waste

is mostly protective clothing worn by workers, tools, and any other material that have been in contact with

radioactive

dust.

Radioactive

waste

is long-lasting. Materials like clothes and tools can stay

radioactive

for thousands of years. The government regulates how these materials are disposed of so they don't contaminate anything else.

Used

fuel

and rods of

nuclear poison

are extremely

radioactive

. The used

uranium

pellets

must be stored in special containers that look like large swimming pools. Water cools the

fuel

and insulates the outside from contact with the radioactivity. Some nuclear plants store their used

fuel

in dry storage tanks above ground.

The storage sites for

radioactive

waste

have become very controversial in the United States. For years, the government planned to construct an enormous nuclear waste facility near Yucca Mountain, Nevada, for instance. Environmental groups and local citizens protested the plan. They worried about

radioactive

waste

leaking into the water supply and the Yucca Mountain environment, about 130 kilometers (80 miles) from the large urban area of Las Vegas, Nevada. Although the government began investigating the site in 1978, it stopped planning for a

nuclear waste

facility

in Yucca Mountain in 2009.

Chernobyl

Critics of

nuclear energy

worry that the storage facilities for

radioactive

waste

will leak, crack, or erode.

Radioactive

material could then

contaminate

the soil and groundwater near the

facility

. This could lead to serious health problems for the people and organisms in the area. All communities would have to be evacuated.

This is what happened in Chernobyl, Ukraine, in 1986. A

steam

explosion at one of the

power plants

four

nuclear reactors

caused a fire, called a plume. This

plume

was highly

radioactive

, creating a cloud of

radioactive

particles

that fell to the ground, called fallout. The

fallout

spread over the Chernobyl

facility

, as well as the surrounding area. The

fallout

drifted with the wind, and the

particles

entered the water cycle as rain. Radioactivity traced to Chernobyl fell as rain over Scotland and Ireland. Most of the

radioactive

fallout

fell in Belarus.

The environmental impact of the Chernobyl disaster was immediate. For kilometers around the

facility

, the pine forest dried up and died. The red color of the dead

pines

earned this area the nickname the Red Forest. Fish from the nearby Pripyat River had so much radioactivity that people could no longer eat them. Cattle and horses in the area died.

More than 100,000 people were relocated after the disaster, but the number of human victims of Chernobyl is difficult to determine. The effects of radiation poisoning only appear after many years.

Cancers

and other diseases can be very difficult to trace to a single source.

Future of Nuclear Energy

Nuclear reactors

use fission, or the splitting of

atoms

, to produce energy.

Nuclear energy

can also be produced through fusion, or joining (fusing)

atoms

together. The sun, for instance, is constantly undergoing nuclear fusion as hydrogen

atoms

fuse to form helium. Because all life on our planet depends on the sun, you could say that

nuclear fusion

makes life on Earth possible.

Nuclear

power plants

do not have the capability to safely and reliably produce energy from

nuclear fusion

. It's not clear whether the process will ever be an option for producing

electricity

. Nuclear engineers are researching

nuclear fusion

, however, because the process will likely be safe and cost-effective.

National Geographic News: Radioactive Rabbit Droppings Help Spur Nuclear CleanupNational Geographic Environment: Nuclear Power—Rising a Comeback

National Geographic Channel: World's Toughest Fixes—Nuclear Turbine

U.S. Department of Energy: Nuclear Energy